GUIDE SPECIFICATION FOR
LAMI-VENTTM LAMINAR FLOW DIFFUSERS
Section 23 37 13 or 158XX
DIFFUSERS/REGISTERS/GRILLES/AIR CONTROL DEVICES
NOTE TO SPECIFIERS: READ & FOLLOW INSTRUCTIONS IN ALL RED CAPS AND DELETE
DIRECTIVES AND OPTIONS NOT SELECTED. ($) INDICATES AN ADDED COST FOR
OPTION/FEATURE.
2.1
SUPPLY DIFFUSERS
A.
TYPE ___ LAMINAR FLOW DIFFUSERS
1.
Diffuser shall be ASHRAE Group E, non-aspirating laminar flow type suitable for
use in critical environments and installation in accordance with ASHRAE Standard
170 for Operating Rooms.
2.
Manufacturer’s published static pressure performance data for 24” x 48“ nom. size
with 8” inlet shall not exceed 0.10” w.g. at design point of 30 CFM/sq. ft.
3.
Diffuser shall utilize a two chamber plenum design. Air shall be admitted to the top
chamber through an inlet collar and inverse conical balancing mechanism. The
balancing mechanism shall be adjustable by turning a screw from the room side of
the diffuser.
4.
The diffuser plenum shall be constructed of 0.063" extruded aluminum with mitered,
back-welded corners and 0.040" aluminum top plate. No cracks or gaps in the sides
of diffuser plenum will be allowed. Single chamber designs or designs utilizing flat
or perforated plates to equalize flow are not acceptable. Manufacturer shall provide
hanging tabs for independent suspension. OPTION FOR SPECIFIER
CONSIDERATION ($): Manufacturer shall insulate the laminar flow diffuser with
1-1/2" duct wrap FSK-backed insulation of 0.75lb/c. ft. density to prevent heat gain
and condensation.
5.
A solid, 0.040” aluminum plate with two rectangular cutouts located directly above a
V-shaped diffusion basket shall separate the top and bottom chambers. The lower
chamber shall have a V-shaped, perforated diffusion basket mounted within a
rectangular, perforated diffusion basket to evenly distribute air over the entire face of
the diffuser.
SPECIFIER TO CHOOSE FACEPLATE STYLE BY SELECTING ONE OF THE FOLLOWING
FACEPLATE STYLES:
For standard framed style aluminum faceplate:
6.
Perforated faceplate shall be .050" aluminum. Perforations to be 16% open area for
40 or less CFM per square ft. of module, 23% open area for 45-65 CFM per square
ft. of module, or 33% open area for higher velocities. Manufacturer shall provide
vinyl-coated stainless steel cable safety retainers on two opposite sides to prevent
accidental dropping of faceplate. The diffuser perforated faceplate shall be installed
in an extruded aluminum mounting frame with mitered back-welded corners. No
diffusion component may be affixed to the back side of the faceplate frame. The
back side of faceplate shall be easily accessible for ease of cleaning.
For optional ($) wrap-around style aluminum faceplate:
6.
Perforated faceplate shall be .050" aluminum and shall extend over and wrap around
plate frame on all four sides to assure continuous perforated surface appearance
between ceiling tee frames. Perforations to be 16% open area for 40 or less CFM per
square ft. of module, 23% open area for 45-65 CFM per square ft. of module, or 33%
open area for higher velocities. Manufacturer shall provide vinyl-coated stainless
steel cable safety retainers on two opposite sides to prevent accidental dropping of
Form 4-105, effective 2/2015
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faceplate. No diffusion component may be affixed to the back side of the faceplate
frame. The back side of faceplate shall be easily accessible for ease of cleaning.
For optional ($$) wrap-around style stainless steel faceplate:
6.
Perforated faceplate shall be 20 ga. 304 stainless steel with No. 4 polished finish and
shall extend over and wrap around plate frame on all four sides to assure continuous
perforated surface appearance between ceiling tee frames. Perforations to be 16%
open area for 40 or less CFM per square ft. of module, 23% open area for 45-65
CFM per square ft. of module, or 33% open area for higher velocities. Manufacturer
shall provide vinyl-coated stainless steel cable safety retainers on two opposite sides
to prevent accidental dropping of faceplate. No diffusion component may be affixed
to the back side of the faceplate frame. The back side of faceplate shall be easily
accessible for ease of cleaning.
7.
All exposed surfaces including border trim shall have finish of SPECIFIER TO
SELECT ONE OF FOLLOWING FINISHES AND DELETE OTHER CHOICE
(white baked enamel of suitable quality to withstand typical cleaning solutions and
normal scrubbing commonly used in hospital operating rooms. OR 204-R1 clear
anodized aluminum. ($))
8.
Diffusers located in rooms with gypsum board hard ceilings shall be furnished
complete with mounting frames. Verify exact locations of diffusers with
architectural reflected ceiling plans where shown.
a.
Laminar flow diffuser manufacturer shall furnish individual plaster frames
or extruded aluminum tee and angle framing sections for suspension as
required by diffuser configuration. The tee shall be 1-1/2" wide x 1-7/16"
high and angles shall be ¾” wide x 1-7/16” high. Minimum wall thickness
of the tees and angles shall be 1/8”. DESIGNER NOTE: Centerline to
centerline dimension of each framing section shall be 0.125” per lineal foot
added to the nominal size of the laminar diffusers.
b.
The suspension system shall be factory-welded in sub-assemblies. Where
framing sub-assemblies butt together, the adjoining surfaces shall be
gasketed and mechanically-fastened with self-tapping wafer head screws.
c.
All tees and angles shall be pre-punched on 6" centers for independent
suspension from above spaced at 2’ max.
d.
Manufacturer shall furnish 1/8" thick closed-cell polyethylene gasket tape to
be field installed on the frame assembly to provide seal between diffuser/tee
grid.
e.
The ceiling framing system shall be finished to match laminar flow panel
diffusers.
9.
Acceptable model and manufacturer: Lami-Vent™ by Precision Air Products Co.
No substitutes..
DIFFUSER OPTIONS FOR SPECIFIER CONSIDERATION:
FOR REMOVABLE PLUG BUTTON ($), ADD THE FOLLOWING TO SELECTED FACEPLATE
PARAGRAPH 6. ABOVE: Manufacturer shall provide removable plug button for room-side access to volume
adjustment valve without removal of faceplate.
FOR DIFFUSER WITH SIDE (OR END) OVAL INLET ($), REPLACE PARAGRAPH 2.1, A. 3. WITH
THE FOLLOWING:
3.
Form 4-105, effective 2/2015
Diffuser shall utilize a two chamber plenum design. Air shall be admitted through an
oval inlet collar located on side (or end) of the upper plenum.
SPECIFIER/DESIGNER NOTE: Elongated oval inlet reduces inlet area. Contact
manufacturer for assistance with sizing flexible duct according to project-specific air
volumes.
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TO SPECIFY ALL STAINLESS STEEL LAMI-VENTTM, CONSULT FACTORY FOR SPECIFICATION.
PART 3 – EXECUTION
3.1.
3.2.
INSPECTION/EXAMINATION
A.
The installing contractor shall examine all openings, mechanical and electrical work, and
adjoining and adjacent construction to receive diffusers and plaster frames prior to
commencing this work.
B.
The installing contractor shall field verify that the rough hard ceiling opening dimensions are
as indicated within manufacturer’s submittals. Hard ceiling conditions shall be plumb and
level with square corners to receive frames or framing sections. Openings not acceptable for
installation shall be corrected by the appropriate contractor until conditions are satisfactory to
installing contractor.
C.
The General Contractor shall coordinate corrective/remedial work promptly.
D.
Proceeding with the installation indicates the installing contractor accepts the rough hard
ceiling openings and conditions.
INSTALLATION
A.
Verify location of all components as shown on the manufacturer’s approved submittals.
B.
Where any adjacent welded framing sub-assemblies butt together with half-tees, the adjoining
surfaces shall be gasketed and mechanically-fastened with self-tapping wafer head screws.
C.
Gasket tape provided by manufacturer shall be field installed on the top side of all horizontal
ceiling grid surfaces as shown in ICS manufacturer’s submittal. Gasketing to be installed
after framing surfaces have been wiped clean, free from any construction dust.
D.
Provide inserts, power-driven type anchors, hangers or other Architect / Engineer approved
hanger anchoring and suspension system devices and methods.
E.
Install suspended ceiling hangers plumb and free from contact with insulation or other objects
within ceiling plenum not part of supporting structural or ceiling suspension systems. Splay
hangers only where required to avoid obstructions and offset resulting horizontal forces by
bracing, counter splaying, or other Architect / Engineer approved methods.
F.
Where width of ducts, cable trays and other construction within ceiling plenums causes
hanger spacing to interfere with the location of hangers required to support suspension system
members, install supplemental suspension members and hangers in the form of trapeze or
equivalent Architect / Engineer approved devices. Size supplemental suspension members
and hangers to support ceiling loads within performance limits established by referenced
standards.
Form 4-105, effective 2/2015
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